Phosphorus compounds for flameproofing fabrics

ABSTRACT

ORGANIC PHOSPHOURS OF THE GENERAL FORMULA   (O=P(-CH2-OH)2-CH2-CH2-CO-N(-CH2-O-R)-CH2-P(-CH2-OH)3)+ X-   IN WHICH R IS H OR C1-3 ALKYL AND X IS HALOGEN OR OH, ARE USEFUL FOR FLAMERPROFING TEXTILES, ESPECIALLY TEXTILES INCLUDING CELLULOSIC FIBERS.

United States Patent 3,709,940 PHOSPHORUS COMPOUNDS FOR FLAME- PROOFING FABRICS Wilhelm Flugel, Speyer, Germany, assignor to Dr. Quehl & Co. GmbH, Speyer, Germany N0 Drawing. Filed Mar. 3, 1971, Ser. No. 120,740 Claims priority, application Germany, Mar. 5, 1970, P 20 531.1; Nov. 10, 1970 .P 55 289.0 Int. Cl. C07c 103/30 U.S. Cl. 260-561 P 7 Claims ABSTRACT OF THE DISCLOSURE Organic phosphorus compounds of the general formula CHzOH CH2 This invention relates to new organic phosphorus compounds, and to the treatment of textile materials therewith for fiameproofing.

It is known to treat textiles, particularly textile materials of cellulose containing fibre, with difiicultly inflammable materials, which are known collectively as organic phosphorus compounds. Known materials of this type are for example aziridinyl phosphine oxide (APO), dialkylphosphonocarboxylal-kylolarnide, phosphoronitrilechloride, tetrahydroxymethylphosphonium chloride (THPC) as well as reaction products of THPC and various nitrogen containing compounds (compare German specification 1,045,098)

Particular difficulties arise in fiameproofing textiles of mixed fibre goods, e.g., fibre goods of cellulose fibes and synthetic fibres such as polyamide or polyester fibres.

A process for fiameproofing fibre goods made from mixtures of polyester fibres and cellulose fibres is known in which the fibrous material is impregnated with solutions of ammonium salts of bis=hydroxymethylphosphinic acid. Such an impregnation is not satisfactory from all points of view in practice especially having regard to permanency and toxicological harmlessness.

Finally, a process for improving textile of natural and artificial cellulose containing fibres, as well as from mixed fibre of cellulose containing fibres and synthetic fibres, has been suggested in which the textiles are subjected to the combined action of tetrahydroxymethylphosphonium salts and halogenated alcohols, aldehydes, amines, ketones and/or carboxylic acids or their derivatives or non-volatile halogenated hydrocarbons. Optionally, in this process there can also be included as well as the fiameproofing substances compounds containing primary and/ or secondary amino groups including their methylol compounds. Polymerisable compounds such as acrylamide can also be used, which are reactable with the methylol groups of the tetrahydroxymethylphosphoniurn salt or trishydroxymethylphosphine oxide. If desired the treated textiles can be subjected to the efiect of heat, especially in the region of about 40 to 170 C. By the additional treatments a water or solvent resistance can be obtained.

The object of the invention is the provision of a material for improving textiles, especially for making them flameproof, which in use gives the textiles not only a high flame resistance but also a particular permanency of the effect of the treatment, wherein the textile properties 3,709,940 Patented Jan. 9, 1973 P CC of the treated goods are retained and their technological properties are practically not adversely influenced.

It has been found that certain organic phosphorus compounds giwe good permanent treatment effects on textiles of natural or artificial cellulose containing fibres, especially mixed fibre goods of cellulose containing fibres and synthetic fibres with a synthetic fibre content up to about 70%.

The organic phosphorus compounds according to the invention have the general formula in which R is hydrogen or an alkyl residue of l-3 carbon atoms and X is halogen, particularly chlorine, or OH.

In order to increase the permanency and at the same time improve the creasing properties of such treatments, it can in some cases be of value to use therewith additional wetting agents such as polymethylolmelamine or alkyl ethers thereof. Furthermore it is possible, by using as well carboxylic acid modified alkylol compounds of melamine, cyclic urea etc., to obtain a permanent fiameproof and water repellent effect.

With the treatments provided according to the invention, according to the type of organic phosphorus com pound used and according to the type of fibrous mate rial, a loading of 15-30% of treatment agent is necessary in order to make the treated textiles flameproof as re quired by DIN 53906.

In the practical use of organic phosphorus compounds according to the invention for treating textiles, it is important that the organic phosphorus compounds are substantially wetted with respect to the fibrous materials; this can suitably take place by condensation at tempera tures in the range of 120-180 0., especially 140-160 C., and suitably also in the presence of a reaction accelerator such as o-phosphoric acid, ammonium salts or the like. The length of time for the heating depends on various factors, inter alia on the type of fibrous material to "be treated, the temperature used, and the construction of the condensation plant or apparatus used. Generally good results are achieved with condensation times in the region of 1-10 minutes. In some cases it can be necessary to extend this time somewhat.

It can further be desired that the flameproofed textiles are treated after condensation with an oxidative agent or an oxidising rinsing treatment, in order to remove insufficiently fixed organic phosphorus compound and to make the treated goods wholly non-odorous.

The invention includes also a process for the manufacture of organic phosphorus compounds of the general formula in which R is hydrogen or alkyl of 1-3 carbon atoms and X is halogen, particularly chlorine, which is characterised in that 2 mol. tetrahydroxymethylphosphonium salt are recated with 1 mol N-methylolacrylamide at a pH 'value of 4-8, particularly 6-7, and at temperatures of -140" C., particularly -130 C., preferably under reduced pressure, e.g. in the range of 10-50 torr.

The resulting product can be extracted from the reaction mixture without isolation with a l-3 carbon atom alcohol at room temperature or slightly elevated temperature up to 50 C. in acid conditions (pH value of 1-5).

' The invention further includes a process for the manufacture of organic phosphorus compounds of the general formula in which R is hydrogen or alkyl of 1-3 carbon atoms and X is OH, in which tetrahydroxymethylphosphoniumhalidc, particularly tetrahydroxymethylphosphoniumchloride (THPC) is reacted under such conditions that the entire amount of halide ions, particularly chloride ions, are removed from the reaction mixture and replaced by hydroxyl ions.

A useful embodiment of the process according to the invention is characterised in that 1 mol tetrahydroxymethylphosphonium salt, particularly 1 mol THPC, is neutralized in aqueous alcoholic solution with sodium carbonate at 20-40 C., the sodium halide, particularly NaCl, separated otf, the alcohol containing filtrate is reduced under vacuum and the viscous solution is reacted with stirring and intense cooling with half 21 mol of N-methylolacrylamide added in portions, the reaction being carried out under reduced pressure, particularly from 10-50 torr and then heated to about 100 C.

For the manufacture of organic phosphorus compounds according to the invention tetrahydroxymethylphosphoniurnchloride or bromide are particularly suitable.

The invention is subsequently described with reference to the following specific examples.

EXAMPLE 1 240 grams of an 80% aqueous solution of THPC (1 mol) and 50.5 grams N-methylolacrylamide (0.5 mol) were stirred together and treated with about 10 grams Na C in portions of l-2 grams, until a pH value of 6-7 was obtained. This mixture was then dewatered under reduced pressure (20 torr) and slowly increasing temperature and brought to reaction. In this way the temperature of' the reaction mix is brought to 125 C. and is held at this temperature for about 2 hours. After removal of the by-products formed (essentially NaCl) a water soluble condensation product which at this temperature was viscous, of the following constitution resulted.

Analysis.Calcd. (percent): C, 31.29; 'H, 6.25; O, 33.37; N, 3.64; P, 16.16; Cl, 9.25. Found (percent): C, 30.80; H, 6.35; O, 32.80; N, 3.60; P, 15.80; Cl, 10.60.

Yield: 180 grams=95% of theoretical.

This reaction product was diluted with water to a concentration of about 80% in order to give the necessary handleability in practice.

EXAMPLE 2 01 M. Wt. 383.5

4 moved under vacuum, and the mixture filtered. A viscous water soluble compound of the following constitution resulted:

CHQOH n HzOH H2 HOHzC-P-CHzOH H2011 Analysis.Calcd. (percent): C, 33.2; H, 6.54; 0, 32.20; N, 3.52; P, 15.57; Cl, 8.93. Found (percent): C, 32.7; H, 6.6; O, 31.1; N, 3.4; P, 15.3; C1, 10.9.

The yield amounted to: 170 g.-=% theoretical. This reaction product was diluted with water to the necessary concentration for practical handleability of about 80%.

EXAMPLE 3 A web (l40-gram/rn. of a polyester cotton mixed fibre yarn (50:50) was treated on the foulard with the following bath:

500 g./l. of an 80% aqueous solution of the reaction product of THPC and N-methylolacrylamide (made according to Example 1);

50 g./l. trimethylolmelaminetrimethylether (60% aqueous solution);

50 g./l. orthophosphoric acid (as catalyst);

30 g./l. polyethylene softening agent.

After squeezing out to 80% liquid take-up, the web was dried and condensed at about 140 C. Finally it was subjected at about 60 C. to a weakly alkaline peroxide or percarbonate containing wash, rinsed out and dried.

A material resulted which was loaded to about 30% by the treatment agent. The so treated web was flameproof according to DIN 53906 and according to the so-called match test (British Standard 2963, method A). The flameproof efiect according to DIN 53906 still remained also after 30 machine washes at 60 C.

The textile properties of the fiameproofed material were exceptional, the feel of the goods being practically nonchanged compared to the non-treated goods. The technological properties were good; the wash and wear proper'ties were substantially improved.

EXAMPLE 4 A web (160-gram/mfl) of pure cotton was treated on the foulard with the following bath:

500 G./l. an 80% aqueous solution of the reaction product of THPC, N-methylolacrylamide and methanol (manufactured according to Example 2);

40 g./l. tetramethylolmelamine;

10 g./l. monoammonium phosphate (as catalyst);

30 g./l. polyethylene agent.

After squeezing out to liquid take-up the fabric was dried and condensed at about 160 C. Thereafter it was treated at about 60 C. with a weakly alkaline peroxile gr percarbonate containing after-wash, n'nshed and A web resulted with a take-up of treatment agent of about 25-30%.

The so-treated web was fiameprooi (according to DIN 53906 and match test). The flameproof efi'ect still remained even after 13 machine washes at 90 C.

The technological properties of the treated material were satisfactory; the wash and wear ability was substantially improved.

EXAMPLE 5 240 grams of an 80% aqueous solution of THPC (1 mol) were evaporated under vacuum to about and diluted with about 100 ml. methanol, and the methanolic solution was neutralized with stirring with about 50g. sodium carbonate at 2240 C. The NaCl arising was separated. The methanol containing filtrate was. reduced under vacuum at temperatures of 2050 C. and under reduced pressure (1050 torr). The viscous solution was then reacted with 50.5 g. (half mol) N-m'ethylol-acrylamide, the N-methylolacrylamide being introduced in portions (25 g.) with striring and intensive cooling at 20- 50 C. Thereafter vacuum was applied, and the temperature rose within 2 /2 hours to 100 C. A viscous end product resulted (about 182 grams) which was diluted with about 80 grams water to a 70% solution for better handleability.

Yield: 260-gram, 70% solution, 598% of theory.

The analysis gave the following values: Calcd. (percent): C, 32.90, H, 6.86; O, 39.40; N, 3.84; P, 17.00. Found (percent): C, 33.10; H, 7.10; O, 39.10; N, 3.80; P, 16.90.

For the organic compound according to the invention in which, in the general Formula 1, X is a hydroxyl ion, the following formulae result in which R is hydrogen or alkyl of 1-3 carbon atoms. Molecular weight 365.

EXAMPLE 6 A web (140-gram/m. of a polyester/cotton mixed fibre yarn (50:50) was treated on the foulard with the following bath:

500 g./l. of a 70% aqueous solution of the organic phosphorus compound made according to Example 80 g./l. trimethylolmelaminetrimethylether (60% aqueous solution);

30 g./l. orthophosphoric acid (as catalyst);

30 g./l. polyethylene softening agent.

After squeezing to about 80% liquid take-up, the web was dried and condensed at about 140 C. Then it was treated at about 30 C. with a weakly alkaline, peroxide or percarbonate containing afterwash, rinsed and dried.

A web resulted loaded to about 30% with the treatment agent.

The so-treated web was flameproof according to DIN 53906 and according to the so-called match test (British Standard 2963, method A). The fiameproof effect according to DIN 53906 still remained after 30 machine washes at 60 C.

The textile properties of the flameproofed web were very good, and the feel of the goods compared to nontreated goods was practically unchanged. The technological properties were good; wash and wear was substantially improved.

EXAMPLE 7 A web (160-g./m. of pure cotton was treated on the foulard with the following bath:

500 g./l. 70% aqueous solution of the organic phosphorus compound made according to Example 5;

80 g./l. tetramethylolmelamine;

10 g./l. monoammonium phosphate (as catalyst);

30 g./l. polyethylene softening agent.

After squeezing out the 90% liquid take-up the web was dried and condensed at about 160 C. Thereafter it was treated at about 60 C. with a weakly alkaline, per- 6 oxide" or percarbonate'containingafterwash, rinsed and dried. A web loaded with 25-30% treatment agent resulted.

The so-treated web was flameproof (according to' DIN 53906 and the match test). The flameproof effect still remained after 30 machine washes at C.

The technological properties of the treated web were good; wash and wear properties were substantially improved.

The loss in tear strength was surprisingly small; it amounted to only 0-20%.

While, in the treatment of webs of a mixed polyester/ cotton fibre yarn (50:50) with compounds according to general Formula 1, in Which X=OH, compared to treatment with these webs with compounds of general Formula 1 in which X is halogen, particularly chlorine, just as good fiameproof properties can be obtained, and only small variations in the technological properties, in particular tear strength, in the treatment of webs of cellulose containing fibres, and indeed both of natural and regenerated cellulose fibres, with compounds of the first noted type, very surprising effects are obtained. The loss in tear strength when using the organic phosphorus compound in which X=OH amounts to 020% while in the use of the organic compound in which X is halogen on cotton webs it is somewhat higher.

I claim as my invention:

1. Anorganic phosphorus compound of the general formula:

in which R is selected from the class consisting of hydrogen and alkyl of l to 3 carbon atoms, and X is halogen, the step of reacting 2 mol of tetrahydroxymethylphosphonium salt with 1 mol N-methylolacrylamide at a pH value of 4 to 8 and at a temperature of -140 C.

4. The process of claim 3 wherein the reaction is carried out at a pH value of 6 to 7, a temperature of -130 C., and under reduced pressure.

5. The process of claim 4 wherein the reduced pressure is 10-50 torr.

6. The process for the production of an organic phosphorus compound of the general formula:

onion 0 e O=%CH2CHs-( NCHz0R onion on. x

HOCHr-P-CHaOH in which R is selected from the class consisting of hydrogen and alkyl of 1 to 3 carbon atoms, and X is hydroxy, wherein 1 mole tetrahydroxymethyl phosphonium salt is neutralised in aqueous alcoholic solution at 20-40 C. with sodium carbonate, the sodium halide formed is removed,theelcohol-containingfiltrate is reduced under No references cited.

vacuum, and the viscous solu tion is reacted with Vz'mbl Y N-methylplacrylarnide added in portions-with stirring gnd LEWIS GO'ITS, a y Examiner intense cooling, and is heatecl under reduced -.pressure -to E; GLLOVE, Assistant Examiner about 100 C. n. 5

7. The process of claim 6' wherein the reduced pres- US. Cl. X.R.

sure 1 10-50 torr. inf-136 UNITED STATES PATENT OFFICE h CERTEFECATE CORRECTION Patent No. 0 940 Dated January 9 1973 Inventor(s) Wilhelm FLUGEL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column'4, line 5, that portion of the formula reading -CH OCN should read CH 0CH Signed and sealed this 23rd day of April 19%..

(SEAL) Attest:

EDWARD I LFLETCERJR. C. MARSHALL DANN v Attesting Officer Commissioner of Patents F ORM PO-l 050 (10-69) USCOMM-DC 60376-P69 w 0.5. GOVERNMENT PRINTING OFFICE: I969 0-366-334. 

